The present invention relates generally to methods of fluorination and more particularly to the use of O.sub.2 F.sub.2 for the preparation of actinide hexafluorides, and for the extraction of deposited actinides and fluorides and oxyfluorides thereof from reaction vessels.
Fluorinating agents useful for removing deposited actinide metal and compounds thereof from surfaces, and for preparing volatile actinide hexafluorides from their very stable solid tetrafluorides, oxyfluorides and pentafluorides are known. However, the difficulty with all of the known materials which are capable of performing these tasks is that little reaction takes place at or below room temperature. The requisite high temperatures (typically in excess of 300 C.) and harsh oxidizing environments result in the deterioration of any containment vessels and transfer equipment as well as in the destruction of the articles to be cleaned and the intended end products, the actinide hexafluorides themselves. Moreover, the reaction of the fluorinating agents with every warm surface in their pathway has made it very difficult to introduce the fluorinating agent into regions of interest. Atomic fluorine, a preferred fluorinating agent for the above-described tasks, is usually generated by microwave radiation, but the overall fluorination process is very inefficient.
Dioxygen difluoride was first prepared and isolated in 1933. A careful investigation of the properties of this material was performed by A. G. Streng in and presented his article entitled "The Oxygen Fluorides" published in Chem. Rev. 63, 607 (1963), the disclosure therein hereby being incorporated by reference herein. Of particular interest in this article is the mention by the author of the explosive reaction of O.sub.2 F.sub.2 when placed in contact with a sheet of platinum covered with platinum fluoride at 160 K. Even at this low temperature, it would appear that O.sub.2 F.sub.2 is unstable in the presence of metallic surfaces. The use of O.sub.2 F.sub.2 for removing actinides and/or actinide containing compounds from metal surfaces would then be impossible especially if the O.sub.2 F.sub.2 had to be introduced into the region of interest through metallic plumbing.